In terms of alcohol and drug policy, Donald Trump remains somewhat of a mystery. On the one hand, he went on the record in the early 1990s calling for the legalization of all drugs, period. Since then, however, he has flip-flopped several times on the issue of cannabis legalization, most recently seeming to oppose legalization for recreational use while supporting legalization for medical use, and even on recreational use contradicting himself by saying that we should "leave it up to the states" (which really means supporting federal legalization without actually saying the "L-word"). And if that does not result in result in enough head-scratching on the part of the reader, he has nonetheless nominated the racist, uber-conservative drug-warrior Jeff Sessions for Attorney General, who "joked" that he thought that the KKK was fine until he found out that they smoked pot. Yes, he actually said that. And Mike Pence would likely be no friend of legalization either, at least from what we gather so far.
As for Trump's position on the drinking age, he does not seem to have a clear position either way. On the one hand, he himself is a teetotaller because he lost his older brother at an early age to alcoholism. On the other hand, despite his right-wing authoritarian and proto-fascist tendencies he seems to be one of the least likely to adhere to conventions or traditions compared to any of the other candidates he ran against in any political party. Thus, on both the drinking age and the War on (people who use a few particular) Drugs, he remains a wildcard. Like a cross between a joker and a jack(ass), basically. We at Twenty-One Debunked do NOT support him by any stretch of the imagination, and Ajax the Great voted for Bernie Sanders in the primary and Hillary Clinton in the general election. But if he does somehow manage to budge in our direction on those particular issues, we will effectively stand with him on those issues while still opposing him nonetheless on practically all of the other issues. And we are indeed prepared for him to flip-flop numerous times while in office as well, as we see that he is clearly quite fond of doing.